Tractor mounted implement



DCC- 143 1954 R. s. REAvEs ETAL TRACTOR MOUNTED IMPLEMENT 3 Sheets-Sheet l Filed NOV. 16, 1951 Dec. 14, 195,4 R s. REAvEs E1-AL 2,696,773

l TRACTOR MOUNTED IMPLEMENT Filed NOV. 16, 1951 I5 SheetS-Sheet 2 De@ 14, 1954 R. s. REAvE's ET AL TRACTOR MOUNTED IMPLEMENT 3 Shets-Sheet 3 Filed Nov. 16, 1951 United States PaterrtfOtl 2,696,773 Patented Dec. 14, 1954 Cioe TRACTOR MUNTED IMPLEMENT Roberts: tReaves, 'West- Salem, Wis.,and LaurelR- Ye'ske,

La Crescent," Minn., assignors 'to Allis-Chalmers -Manu- -l factoring Company, Milwaukee, Wis.

'Application November 16, y1951,l SerialNo. 256,758

f9 Claims. (Cl. 97-46.07)

above, the -nature'of the tools andof the rwork to be `performed-maymake"it-desirable to provide -for free floating movement ofthe front and rear tools relative to the `trac- `tonand to veach other. Also, when the machinel cornes -to V.the end of arrow, it is usuallyldesirable -thatthe tools be lifted in sequence so that 'the forward'tools and the -rearward `toolsrnay leave thegroundonuthe: same' line 'at the end of 'the'field l Variations-in soil conditions arid in the. ground contour `also may make itdesirable to provide a method of mounting forward and rearward tools so that they will respond .-to uctuations inwerking-load to actuate a .lifting device which -will 'change the yworkingdep'th of the `toolsan amount proportional `to the. increase or `decrease. in' load and thereby maintain .a constant load on.`the tractor at all times.

I Generally, it is an objectv of .this Ainvention to providefa tractor implement combination whereinvtools are mounted at the. front and atthe rear of 'the tracton and which `incorporates all of .fthe hereiiibefore i `outlined `desirable features.

One ofthe more specific objects oftthisinvention is to :provide a tractor implement combination wherein front and rear ntools and an associated' lift mechanism are arranged in such a manner that the front tools at the opposite sides of the tractor and the-rear toolsmay float -up and -down f relativeu to the tractor `'andliridependently of t each other without." impediment by ,the .lift mechanism.

. Afurther object of thisinvention-is to provide a tractor implement combination of the hereinabove outlined 'character in which the'slift mechanism isV automatically controlled -to maintain. a substantiallyconstanfdraft load'. on

the tractor. y n y I ,Astill further. object ofthe Invention 1s.to1,provide`an i irnprovedl.implement4 lift mechanism which may be .used

. withfront andV rear mounted .'.draft regulated implements,

and which provides for sequential' lifting and loweringiof the front and rcartools so that, lin approaching the end of row, the rear tools may be raisedfrom thetground `Ysubsequently tog'the raisingof thelfrontltools, andso'that at the start of a new row the rear tools 'maybe lowered -subseqnentlyto the lowering of Athefront tools.

"The foregoing and other objects and advantages are attained bythepresent invention, variousi-novelffeatures of which will .be apparentrfromthe descriptionlherein ,and theaccornpanying drawings 'disclosingfan embodiment of the invention, and will be more particularly pointed out in the appended claims.

In the drawings:

.Fig l is asideelevationof 'a'tractor implementcomybination which embodies' 'the .present invention and which lhas 'the near rear wheelrern'ove'dfor purposes of exposure;

)FigfZ is aplan' view 4of the tractor implement combination "shown: in "Eig i1 with upper portions vof the 'tractor omitted; )Figi-t3 is Jappartial -perspective view v.Tof the ffront impleme'nt mounting structure and lifting mechanismshown in Figsfl and 2;.and K Fig. '4 isa front elevation of the front implement mounting structure shown in- Figs. land 2 with the tools and other parts omitted fromthe mounting structure.

.Referring to"Figs.'l and r2 of the drawings, the apparatus chosenC to illustrate the present inventioncomprises a tractor 1 having a pairof rear driving wheels '2 and front 'dirigible wheels 3 supporting a tractor main frame 4, andimplements includinga pairof front mounted bedders 7 anda rear mounted bedder 8.

Mounted 'forward of and below the rear airlehousing' ,11 of the tractor is .a draft control arm` 12 Whichyas will appear more' fully hereinb'elow, servesas part-cfa hitch means.' for` connecting' implements inyfdr'aft transmitting relation to the tractor. l\Rigi`dly secured to 'theunderside vof the tractor .is ab'rack'et'rlS on whichithe control arrn'12 is pivotally mounted by means of. a cross pin'lfl'for'` fore and aft'swinging movement in response to changes' in implement. load. The control arm 12 a'ctuates a control linkage of'an automatic draft regulating appai'atusin conformity with established: principles as disclosed, for

` instance,l in a-cope'ridin'gapplication Serial No. 30,348, filed on'Iune'1,"1948,'by'Walter F. Strehlo'w et alffor Power LiftMeans vAffording Depth'Control and Sequential Raising and Lowering'of Implement-s, now U.' S. Patent 2,611,306, issued 'September 23, 1952. l

Y Features of the tractor implement combinationidisclosed herein' 4are claimed jin the aforesaid Strelilow 'et al. applicationand-also in application Serial No. 29234 fild `-May 26, 1948, yby Walter F. Strehlow for'LiftfMea'ns Aifording Depth Regulation of TractorA propelled-` Imple- `in alignment withcorresponding aperturesdntlieother bracket 19 and also with` vertically spaced transvers'bores in the lower portion of the draft control arm 12. 'The alignedopenings'ofthe brackets and ofthe control arm 12 receive the pins'14'and 16, respectively; for detachably connecting the draft pin assembly13 to the draft control arm l2. It will bel noted that pin14 performs the 'dual function of ,pivoting the control arm 12 on thebrac'ket 15, and ofsecuring the draft pin'assemblyzl 'against pivotal movement about .the pin 16 relative' to the control `arm 12. The vends of the draft. pin 17 vaffordV pivotal 'sup- `ports for` the rear ends of a pair of lower' push linksZl,

and also for the front ends of'a pair of lower drag links '22. Mounted'forwardlry of the opera'torsstation,.23v on the ltract'onaridv in overlyingVrelationtothe tractor' main frame 4, is'a'transverse r'ockf'shaft or 'lift s'haft24 which is 'rotatablysupported by'a 'pair' of; straps 26 fixed, respectively, toioppositeside channelso'f the tractormainf'rame. As best shown in Figs, l and '-3, `a lower'lift arm 27 is rigidlyattached to the lift'shaft' 24 in 'depending relation .thereto at the left side ofv the' tractor. The free end'o'f `the lower lift arm `27has apivotal connection 28 with the end of apiston'rod'29vvhichforms'part` of 'a hydraulic ram'31. The cylinderpartfof t-he ram '31 ispivotally mounted on a pin 32 .carried'by a bracket3'3 whichis Xed to .theleft side vchannel of the tractor main-frame. The.piston=rod-29 of the. ram 31 'may .be actuated byadmission of pressureuidfinto theram cylinder-to swing the lowerfliftrarm-f27 forwardly and upwardly. -Fluid for'actuatingthe rarnf31 is suppliedfby avhydraulic-pump 36 whichfis-indicatedinFig. y-2 and which derivesgpower from the Atractor engine '37 .-in -conventional manner.

Al?'ressi.1reuid is conducted from the` pump 36 to the ram 31 `through one of a pair of conduits.

The. left-rend of .the lift .shaft 24 isaXially v.extended outwardly/beyond fthe lower'lift .ar-m27 to ,.provide a vpivot on wh-ich. is mounted "a forwardly extending upper link orlift liri'kf39. '.Thelo'werlpoitio'n fof the.' lower lift the tractor to form a nger 41 which is cooperable with an actuating arm 42 which is rigidly attached to and extends downwardlyl from thc lift link 39. As the piston rod 29 of the ram is extended and the lower lift arm 27 swings forwardly and upwardly, the finger 41 which engages the actuating arm 42 at its rear surface causes the lift link 39 to swing upwardly with respect to the tractor on the axis of the lift shaft 24.

A lift mechanism corresponding to the one shown in Fig. l at the left side of the tractor is mounted at the right side of the tractor as shown in Figs. 2, 3 and 4, and comprises a lower lift arm 43, a ram 44 and a lift link 45. The explanations hereinbefore regarding the construction and operation of the lift mechanism at the left side of the tractor similarly apply to the lift mechanism at the right side of the tractor. The lower lift arms 27 and 43 are rigidly attached to the lift shaft 24 for simultaneous movement with each other but the lift links 39 and 45 are pivotally mounted for movement independently of each other and of the lower lift arms.

Referring to Figs. l and 2, the forward ends of the push links 21 are pivotally connected by pins 48 to a forward implement mounting structure, generally designated by the reference character 51. In like manner,

the forward ends of the lift links 39 and 45 are pivotally connected to the front implement mounting structure by means of pins 49. The push links 21, lift links 39 and 45 and associated parts represent means for positioning the front implement mounting structure 51 at the forward portion of the tractor for up and down movement with respect thereto.

The front implement mounting structure 51 consists of a bar 52 which extends transversely of and in underlying relation to the tractor main frame 4. As best shown in Fig. 4, two bracket structures 53, 56 and 54, 57 at opposite sides, respectively, of the tractor are rigidly attached to and extend upwardly from opposite ends of the bar 52 and are arranged in transverse alignment with each other. The two bracket structures comprise inner brackets 53 and 54 and outer brackets 56 and 57. The outer brackets 56 and 57 are bent inwardly and upwardly at their upper ends to join with and be rigidly secured to the upper ends, respectively, of the inner brackets 53 and 54. Straps 58 are rigidly secured, respectively, to the inwardly bent portions of the outer brackets 56 and 57. The straps 58 have apertures in alignment with apertures in the upper portions of the inner brackets 53 and 54, respectively, for receiving the pins 49 by means of which the bracket structures are pivotally connected, respectively, with the forward portions of the lift links 39 and 45. A tool mounting bar 59 extends outwardly at the left side of the tractor and is in axial alignment with a corresponding tool bar 61 at the right side of the tractor. The tool mounting bars 59 and 61 are rigidly secured to the bracket structure 53, 56 and to the bracket structure 54, 57, respectively, so that the transverse bar 52, the bracket structures and the tool bars 59 and 61 form a rigid structure. The bedder 7, a gauge wheel 62 and a coulter 63 are conventionally mounted on the tool bar 59 at the left side of the tractor forwardly of the left tractor rear wheel 2, and another bedder 7, a gauge wheel 62 and a coulter 63 are conventionally mounted on the tool bar 61 at the right side of the tractor forwardly of the right tractor rear wheel 2.

The pins 48 which pivotally connect the forward ends of the push links 21 to the front implement mounting structure are mounted on the outer brackets 56 and 57, respectively. Each push link 21 is bifurcated at its forward end as shown in Fig. 4, and the inner legs of the push links 21 are pivotally connected with the inner brackets 53 and 54, respectively. by the pins 48.

Referring to Fig. l, a roller 66 is rotatably mounted on the tractor by two brackets 67 and 68 which are rigidly attached to the left side channel of the tractor main frame 4. A similar roller 69 is mounted in the same manner on the right side channel of the tractor main frame. The rollers 66 and 69 are disposed between the tractor main frame 4 and the inner brackets 53 and 54 to provide centering bearings for the front implement mounting structure 51.

A rear lift shaft 71 is rotatably supported on the tractor in transverse relation thereto and rearwardly of the rear axle housing 11. As best shown in Figs. 1 and 2, a bell crank consisting of a rearwardly extending arm 72 and a depending arm 73 is rigidly attached to the left end of the shaft 71 for turning movement therewith. The other end of the shaft 71 at the right side of the tractor rigidly mounts a rearwardly extending arm 74 which is in transverse alignment with the rearwardly extending arm 71 at the left side of the tractor. The free end of the depending arm 73 is pivotally connected by a pin 76 to the rear end of a fore and aft reciprocable link 7'7, and the free ends of the rearwardly extending arms 72 and 74 are pivotally connected, respectively, by pins 78 and 79 to the rear implement mounting structure, which is generally designated by the reference character S1.

The rear implement mounting structure 31 comprises a transverse rear tool bar 84 which has an upper bracket 82 and a lower bracket S3 rigidly attached to one of its ends at the left side of the tractor, and which has another upper bracket 86 and a lower bracket 87 rigidly secured to its other end at the right side of the tractor. The rear tool bar 84, the upper brackets 82 and 86 and the lower brackets 83 and 87 form a rigid frame structure for mounting and positioning a rear bedder 8, a coulter 88 and a gauge wheel 89. The lower brackets 83 and 87 are pivotally connected, respectively, with the drag links 22 at opposite sides of the tractor by pins 90.

The reciprocable link 77 extends forwardly and upwardly at the left side of the tractor as viewed in Fig. l. and is pivotally connected by a pin 91 to the upper end of a guide link 92. The lower end of the guide link 92 is rotatably mounted on the lift shaft 24 for fore and aft swinging movement independently of the lift shaft 24, lower lift arms 27 and 43, and the lift links 39 and 45. The lower lift arm 27 at the left side of the tractor is upwardly elongated so as to extend above the lift shaft 24 and form an upper lift arm 93 to which an offset lug 94 is rigidly attached. As best shown in Fig. 3, the offset lug 94 has a transversely extending part 96 which mounts an adjustable screw 97. The head of the screw 97 moves into Contact with the guide link 92 and swings it rearwardly upon extension of the arms 31 and 44 in tool raising direction.

A trip lever assembly, generally indicated in Fig. 3 by numeral 101 consists of a hand lever 102 which has a forwardly extending latch arm 103 rigidly secured thereto. The lever 102 is pivotally supported by a pin 104 on an angle bracket 106 which is rigidly secured to the left side channel of the tractor main frame 4. The latch arm 103 of the lever 102 is double bent outwardly and then forwardly near its forward end to form a transverse shoulder 107 thereon. A lug 109 is rigidly attached to a midportion of the reciprocable link 77 and extends inwardly toward the tractor. At its extreme forward end, the latch arm 103 has a sliding or inclined surface 10S for camming engagement with the lug 109 when the rear tools are raised from their lowered position while the hand lever occupies a forwardly tilted position, as will be explained more fully hereinbelow. The reciprocable link 77 is prevented from moving in rear tool lowering direction, that is forwardly, when the shoulder 107 occupies a blocking position ahead of the lug 109. An overcenter spring 112 which is connected at its upper end to the hand lever 102 and at its lower end to the bracket 106. serves to hold the lever in the position in which it is shown in Figs. l and 3, and also` if desired, to hold the lever in a forwardly adjusted position in which the shoulder 107 lies within the path of the lug 109.

As shown in Fig. l, a stop rod 113 is pivotally connected by the pin 76 to the depending arm 73 of the rear rock shaft 71. The forward end of the stop rod is free to slide in an aperture of the bracket 33. A stop collar 114 is adjustably secured on the stop rod 113 to provide a stop when the collar cornes into Contact with the bracket 33. The stop rod 113 and collar 114 provide a means for limiting the working depth of the rear bedder 8, in particular, when a rear gauge wheel 39 is not used. Furthermore, the stop rod makes it possible to obtain automatic depth regulation of the rear implement as will be explained more fully hereinbelow.

The apertures in the rear ends of the links 39 and 45 which receive the lift shaft 24, and the apertures in the front ends of these links which receive the pins 49, as well as the apertures in the push links 21 which receive the pins 4S are made oversized so that loose pivotal connections are provided. These loose connections, in conjunction with the rollers 66 and 69, make it possible for the' tractor to tilt to either side respect 4to the front implement mounting structure 51.

In Fig. 1 -the `front and `rear imp-lement mounting structures 51 and 81 are shown in limplement lowered positions. The lifting rams 31 and 44 which 4are ymounta-` ed on opposite sides of the tractor and connected yto the lower lift arms 27 and 43 may be actuated upon manual control of the hydraulic system lby the 'tractor operator to bring about extension y.of the rams. The extension of the rams causes the lift arms `27 and 43 to rotate for? wardly and upwardly. As the lift arms rotate, the fingers' 41 at their lower portions `'push against theactuating arms 42 vto bring about lifting of the front implement struc, ture S1. Shortlyl uafter the lfront bedders 'l are lifted from vthe ground, the screw V97 of the -upper 'lift arm 93 cornes into contact with the lguide link 92. Continued extension of the grams 31 and 44 andnconsequentA rotation of the lowerlift arms 27 and` `43 .and Aofthe upper `lift arm 93 causes'the guide link y92 to` be swung rearwardly. This rearward swinging of thewguide link 92 causes 4time reciprocable link 7'7 to -rnove rearwardly, .ther-eb;I rais: ing the rear'bedder 8 to an inoperative position and eventually to a' transport position.

During iield operation,'when the-machine approaches the end of the field 1with the bedders# and 8 ,in operaf 'tive ground vengaging positions, the operator may by manual control of the hydraulic system cause-rotation `4off the forward rock shaft 24` in 'implement raising Qdi.- 'recton so that the lforward rimplementmounting struc,- 'ture 51 will be raised and, as the tractor moves `foutwardly, the screw 97 -on the lupper litt arm 93 will en- A'gage with `guide yllink `92 and bring about vthe ,subsequent Llilfting of the rearward implementmounting structure 81. As -a result of such sequential lifting, v'the -front bedders f7 and the `rear bedder 8 .will Vbe raised on the sameztransf "verse iline. The adjustable screw '97 on the upper lift 93 .permits adjustment of fthe time interval in :the ting of 'the tf1-ont :and rear atools.

'The 'hand .lever .102 .is mormally maintained by fthe spring i112 Lin .'a #forwardly acliusted` position zso fthat, as the rear bedders are lifted, the projecting lug 109mm fthe :reciprocabie link 77 #will come zinto camming engagement with the :inclined surtiace 1108 on the Flatch arm 1103. Continued rearward motion .of the freciprocable link 77 y'will brinfg about :a positioning tot the V.pitojeoting'v1-ng L09 to theV rear of tthe :shoulder A1107 :on the :latch arm 105. TWhen the ifrear implement mounting structure 1.81 tis .raised to an :inoperate position, the-weightiof the Ystrucftnre has a tendency vto moMe mhe ireciprocable -`link 517 forwardly. `However, ythe engagement of A.the shoulder l, i1027 of the latch Varm *103 with the projecting lug "109.011

-the reciprocable link T77 prevents' .the -timplements tfrorn freturning to :a :ground working positioniuntil the operator .manually releases :the recipnocable ilinkji zby :rearwardadjustment ,of fthe lever v51'02 to 'the position in iwhxch the :In returning lthe bedders '7 :and 8 tto :a `ground iengagting position, tth'e .-:operator, -fby ;a @manual control .of .the :hydraulic fsystem,xcauses the extensible rams '8i :and .4;4

to contract therby epermitting the #front implement nnounting structure 5.1 rto y@descend When iit lis" desired Ithat the rearV bedder be flowered to 1an -qoperatrve post- `'tion it is -rnecessary fthat Athe operator `manually :release @the Areciproca-ble :link '.77 from its looked condition "by lmoving -`the lever 102 rearwardly, @thereby moving @the `shoulder =1'07rout:of `.engagement with-fthe -lug 109. I,'lhis A rmakes it possible for the v#operator @to fmanually :achieve :La :sequential 'lowering :of the rfront :and mear t implements to :ground working positions @Referring tto ^Fig. 1, l'it will ghe fnoted :that when fthe :machine tis toperateii with -the ifront libeddens rl 'and the frear vbedder t8 in t ground engaging .positions, z tdraft y'force lwill `ibe transmitted to rthe tdraft ,cont-rol larm y1f2vthrough the push links 21 and yalso zthrough theydrag links 212. -Variationsof-the soil lresistance encountered by:t-he:bedgders 'will '.'therefore abe transmitted to -thecontrol r.arm 12 tofthe azautomatic t draft .control apparatus. Increases and reduc'tionsin'the workingfloadwill cause the A control arm '12 .tobei pivotedin opposite@ directions, tandas a resultthe .hydraulic fsystem wi1ll bef'automatically actuated: tog-admit .'pressure uid from; therpnmp: 3,6tow the-rams 31 land .44 for .ftol'piermitsemissiont of :pressure luidffrom zthe-,rams. ,For riexample, was fan fobstruction is aencountered fvby either .fof theafrontbedtlers;thelload-fisttransmittedftoithe automatic idraftfcontrolllinkage. Tt-iswausessextcnsion :ftbe-srams' i6 ta'ndALa predetermined :amount which is `fproportinnal to .the increase .of fthe ,working `:load imposed .Lupen tthe tractor. The extension of the ramst'cause-fthe -frontbedders .to beflifteda slighttamountfffso that the draftis de- ,creased to the :desired .predetermined amount. Actuat-ionofithe/rams-to raisesthe tirent-.bedders ,to compensate for draft finereaseidoes .not rbring :about automatic lifting of @the .rear f-bedder :8. Bowen-ex", in ...implements .of I this `type .where'threeebqttoms Yarelistzllnit istcommon totspace the rear twheels :2 .of .fthe tractor so tthat they run ,lin the iurrows {effthe forward bedders 7. .fIftthe stop `rod '1;13 is used to 11n-,nit Ethe working `depth of fthe rear ,-bedder VV8, anydepth regulation ofltheifront bedders 7 .willindireetly .aiieqtlthe frear lbedder 8. :Fornsxatrlple7 tif :an area. of :firm :soil :is encountered l:which causes `the tdraft :load .-.to increase on :all three bedders, Iall three will :cause actuationtoffthecontrqltarms12fandzthereforeioftthe'automatic draftrregulating:apparatus :Qnlyttherront bedders will directly:respond `itoitheextension.roffthe :rams :31 and .44. However, fthefextension of. theframstwillLcause' the ffurrows formed by fthe tfrontebottoms :7 .to :become .shallower, :and `.when lthe :.-rear twheels 2 of the :tractor `.ride l,up `on `the shallower .turrows, ltheyi,ifvillicause @the rear :bedder 8 to i-'be raised ,an `amountequal to :the raising -of the rear nvheels of the ttractor.

From Y the fforegoing -it will rbeseen fthat fall.. three ,-bedders are operative to actuateftheautomaticfdraftcontrol kapparatus but ionlythe ,frontftools rcspond -directly tof extension Qf- `.the fhydraulic rams. The near ftools respond .'ndirectly :through the raising ,chtite `:rear wheels 0f Vthe .'tfaQtQL :In .operation in 1th@ held. .whenonmof the forward v'aange wheels 62 or thezrearward 'gauge'wheel 8 9 vrides ioseriafhump Qrfsirnilar olsstaclefthe associ .ediimplsmsut une tingistrusture willv hetfrse :to fraisetpr.. oat upwardly hrt-he gauge wheel- -ilttfshouldfbewnoted fthat @one Aof ls dffor ,slrattfresulationer'sequential .e in anyiwsyithsfreeflloatmgmovement ,e sont :and tsar iimplsmsnt mounting structurestranne of :tres filoating tof .the `i:nplsrftsnt rmeunting .structures extends @from lowered :working positions f1.0 .the raisedttranspsrttrositisns further-more, the from .engineer implement .ffmounting structures :5,1 and `81 are to illqat independently fof ...ash Qthsr- `ln rrough 2fis=ksptinits noperstivefposition-fin tEigs `1 and :3;fs0 thstwhsn the-'rear heartily, thefshnulslertlll? .densamenea sw'thtthsflilelll9ftofprsrsnl;return of thsrearflbedder on Orzmal lowered position t ,inbsfsre .the nvslcsonnstions Qf-the 4,5' to the from implement mounting tothe-lift Shaft f2.4, as well asfths nnsGtiQIsst-sftthtnnsh;lialssfll, .are flttedlloossly it-thst-raG-torto assumefafssmswhstlstsrally tllts ,rpositismwith rsspeettofths fmnimplsmsnsmummg structure 51. This arrangementpermitswthebedders 17 ftpnnaintsin thsirfproasrfdspthwsnithoushfthe tractor is @au .d ts---thb shsnvgssftinfssntsurfsfsthe vgrstmd- If-at nyttinte oneiofghe front-'beddersfshould vbegin .o0 f1.0 ke ashellswsnfurrowthan,thsfothsrfrsntilssddsr, the f yr mplernent turei-willjbefcaused to till will. .sp ,.-Suh'ttiltiris will Icause ftheactuating armfloffthe lift link =39 or 45,.',as {ther-@asentarse .tofmovsisursfx sslllstiV wifhthefn-sr 41 .fofgthe .lower'lift arm on-therespective-side of the ztractor. Fonexamplenwhenthefbedder 7,-on the left .-sideofgtheitractor, asxviewledin ligfl, is =lowWiih-respect he bedderfon the ight-isdefof--the traetorptherpllsh A M .A2 ,atgthe-vright ideofithetractorgwvill disengage frorpsthedngen .I yon'the-lowenl-ift armiflfonrthetright iside Qffthettras er -Withvthebsildsrsfin thisrpostion. .any :increase in (draft load lTwill -acluate the automatic (draft fcontrol apparatus a to i bring about f an. extension lof thel xamsgilffandv 44. `Asfzthe -ramscntencl7 the: lower" lift y75 :.armsv27 k:and-A3 lswin'gffor-wardly butonly=the"bedderton ftheleft side of thetractornwiiltfbe raised. Raising -of I'ft-heabedder-on the leftsideof the tractor will continue gluntilboth-'frontibeddersare .atrthet same rdepth, `lhis iis 'aso becausenthelnger 41`fand-thepush arm'42'are engaged gg with-eachother-only.ontheleft sideofithetraetor. After stile-working fdepths of'bot-h fronty bedders f7 have' become aequal, .fany' ,ffurther t movement lof -the lower i lift `arms 27 ,sa d 43'will affect bothbeddersjintheisame manner.

shouldtfbefnnderstoodthatit .notintendedvtoflirnit innentionftoftheparticular. grmsasd details-herein l disclosed, and that the invention includes such other forms and modifications as are embraced by the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

l. The combination of a tractor, a front implement mounting structure, a rear implement mounting structure, a double armed lift lever pivoted on said tractor for back and forth swinging movement in implement lowering and implement raising directions, an upper link pivoted on said tractor coaxially with said lift lever and having a forward end portion pivotaly connected with said front implement mounting structure, a pair of lower links mounted on said tractor for swinging movement relative thereto and relative to each other on a pivot center in downwardly spaced relation to the pivot center of said lift lever, pivot means connecting said lower links, respectively, with said front and rear implement mounting structure, a rearward rocker arm pivoted on said tractor and being operatively connected in lift force transmitting relation with said rear implement mounting structure, a one-way actuating connection between one arm of said lift lever and said upper link, and another one-way actuating connection between the other arm of said lift lever and said rearward rocker arm, said actuating connections being operative to raise said front and rear implement mounting structures upon rotation of said lift lever in said implementing raising direction.

2. In combination with a tractor having a main body and a draft element operatively connected with and depending from a rearward portion of said main body, a double armed lift lever mounted for rocking movement on an axis extending transversely of said main body between the front and rear ends of the latter and in elevated relation to said draft element, a front tool mounting structure, a forward link system including a lower and an upper link pivoted, respectively, on said draft element and on said axis for positioning said -front tool mounting structure at and in vertically adjustable relation to a forward portion of said tractor main body, a rear tool mounting structure, a rearward link system including a draft transmitting link pivoted on said draft element and extending rearwardly therefrom for positioning said rear tool mounting structure rearwardly of and in vertically adjustable relation to said tractor main body, a lift force transmitting element operatively connected with said forward link system for cooperative engagement with one arm of said lift lever upon swinging movement of the latter in implement raising direction and movable away from said one arm of said lift lever upon self-adiustment of said front tool mounting structure upwardly relative to said tractor, and means affording a one-wav actuating connection between the other arm of said lift lever and said rearward link system and operable to raise said rear tool mounting structure upon swinging movement of said lift lever on said axis in said f implement raising direction.

3. In combination with a tractor having a main body and a draft element operatively connected with and depending from a rearward portion of said main body, a rock shaft mounted on and extending transversely of said tractor main body between the front and rear ends of the latter and in elevated relation to said draft element. a pair of front implement lift levers rigidly connected with said rock shaft at opposite sides, respectively, of said tractor main body, said front implement lift levers being adiustable to implement lowered positions in depending relation to the axis of said rock shaft and being swingable forwardly from said implement lowered position upon rotation of said rock shaft in implement raising direction, a front implement mounting structure extending transversely of said tractor main body at opposite sides of the latter. a pair of link systems at opposite sides` respectively, of said tractor main body and each including a lower and an upper link pivoted` respectively, on said draft element and on said rock shaft for positioning said front implement mounting structure at and in vertically adinstable relation to a forward portion of said tractor main body, a pair of actuating arms rigidly connected, respectively, with said upper links and having end portions forwardly of and in abuttable relation to said lift levers, respectively, so that self-adjustment of said front implement mounting structure upwardly and downwardly relative to said tractor main body will move said end portions vof said actuating arms out of and into cooperative engagement, respectively,

with said lift levers, a rear implement mounting structure, a rearward link system connected with said tractor for positioning said rear implement mounting structure at and in vertically adjustable relation to a rearward portion of said tractor main body, a rear implement lift lever rigidly secured to said rock shaft, and a one-way actuating connection between said rear implement lift lever and said rear implement mounting structure and operative to raise said rear implement mounting structure upon rotation of said rock shaft in said implement raising direction.

4. The combination of a tractor, a front implement mounting structure, a rear implement mounting structure, a double armed lift lever pivoted on said tractor for back and forth swinging movement in implement lowering and implement raising directions, an upper link pivoted on saiditractor coaxially with said lift lever and having a forward end portion pivotally connected with said front implement mounting structure, a pair of lower links mounted on said tractor for swinging movement relative thereto and relative to each other on a pivot center in downwardly spaced relation to the pivot center of said lift lever, pivot means connecting said lower links, respectively, with said front and rear implement mounting structures, a rearward rocker arm pivoted on said tractor and being operatively connected in lift force transmitting relation with said rear implement mounting structure, a reciprocable link operatively connected at one of its ends with said rearward rocker arm for rotating the latter in tool raising direction upon rearward movement of said reciprocable link relative to said tractor, a guide link pivotally connected with the other end of said reciprocable link and pivoted on said tractor concentrically with said lift lever, a one-way actuating connection between one arm of said lift lever and said upper link, and another one-way actuating connection between the'other arm of said lift lever and said guide link, said actuating connections being operative to raise said front and rear implement mounting structures upon rotation of said lift lever in said implement raising direction.

5. The combination of a tractor, a front implement mounting structure, a rear implement mounting structure, a double armed lift lever pivoted on said tractor for back and forth swinging movement in implement lowering and implement raising directions, an upper link pivoted on said tractor coaxially with said lift lever and having, a forward end portion pivotally connected with said front implement mounting structure, a pair of lower links mounted on said tractor for swinging movement relative thereto and relative to each other on a pivot center'in downwardly spaced relation to the pivot center of said lift lever, pivot means connecting said lower links, respectively, with said front and rear implement mounting structures, a rearward rocker arm pivoted on said tractor and being operatively connected in lift force transmitting relation with said rear implement mounting structure, a reciprocable link operatively connected at one of its ends with said rearward rocker arm for rotating the latter in tool raising direction upon rearward movement of said reciprocable link relative to said tractor, a` guide link pivotally connected with the other end of said reciprocable link and pivoted on said tractor concentrically with said lift lever, a manually operable latch member pivoted on said tractor and cooperable with said reciprocable link for releasably locking said rearward rock arm against rotation in tool lowering direction, a one-way actuating connection between one arm of said lift lever and said upper link, and another oneway actuating connection between the other arm of said lift lever and said guide link` said actuating connections being operative to raise said front and rear implement mounting structures upon rotation of said lift lever in said implement raising direction.

6. The combination of a tractor, a rear implement mounting structure, a rearward rocker arm pivotally connected with said tractor and operatively connected in lift force transmitting relation with said rear implement mounting structure, a link member extending forwardly from said rear implement mounting structure under and pivotally connected at its forward end with said tractor, a lift lever pivoted on said tractor forwardly of said rearward rocker arm for back and forth swinging movement in implement raising and implement lowering directions, a guide link mounted on saidtractor for pivotal movement coaxially with `and relative to said lift lever, a fore and aft reciprocable link pivotally connected at its forward end with said` guide link 4and operatively connected at its rearward end with sa-id rearward rocker arm so as to raise said rear implement mounting structure upon rearward swinging movement of said reciprocable link, and a one-way actuating connection between said lift lever and said guide link operative to impart rearward movement to said reciprocalble link upon swinging movement of said lift lever in said implement raising direction.

7. The combination set forth in claim 6 and further comprising a manu-ally releasable latch mechanism operable to lock said reciprocable link against forward movement tupon adjustment of said rear implement mounting structure to an elevated position relative to `said tractor.

8. The combination set forth in claim 7 and further comprising a biasing spring associated with said latch latch mechanism in locking condition.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,302,502 Morkoski et a1 Nov. 17, 1942 2,324,840 Hippie July 20, 1943 2,352,281 Mott June 27, 1944 2,361,122 Raney et al. Oct. 24, 1944 2,362,578 Mott Nov. 14, 1944 2,611,306 Strehlow et al Sept. 23, 1952 

